At the Jockey Club Round Table this month, leaders of the racing industry gathered to discuss the well-known issues facing the sport, such as the decline in its popularity and the steady erosion of betting totals in the United States. However, a principal subject was one that most fans would not even recognize as an issue, because it was resolved so long ago.

Jockey Club vice chairman Stuart S. Janney III called the drug Lasix “a polarizing topic if there ever was one.” It shouldn’t be polarizing because it is legal in every U.S. racing jurisdiction, with almost all owners and trainers using it on all of their horses. But suddenly a movement calling for its ban, particularly in top-level competition, has gathered momentum:

● The Breeders’ Cup announced in mid-July that it will ban all race-day medications — principally Lasix — from its 2-year-old races in 2012 and from all of its races in 2013.

● The American Graded Stakes Committee, which bestows the important Grade I, II and III ratings upon U.S. stakes races, followed the Breeders’ Cup announcement by declaring that it will deny graded status in 2012 to any 2-year-old stakes race in which horses can run on Lasix.

● The august Jockey Club declared its opposition to Lasix, with Janney telling the Round Table, “We believed this industry is best served by taking steps . . . toward medication-free racing.”

The pro- and anti-medication camps have argued for decades about whether Lasix gives horses a competitive edge or whether it is a purely therapeutic substance that, as a diuretic, controls the tendency of thoroughbreds to bleed in the lungs after strenuous exercise. The pro-Lasix side, led by the Horsemen’s Benevolent and Protective Association and aided by racing veterinarians, won the fight in the 1970s, persuading racing commissions across the country to adopt a policy of “permissive medication.” Their winning argument was one that turned out to be a falsehood.

Horsemen and vets maintained that, in the new era of year-round racing, thoroughbreds could not withstand the increased rigors of the sport with the traditional regimen of hay, oats and water. They needed medications such as Butazolidin and Lasix. At the time, the average American thoroughbred made more than 10 starts a year. Since the liberalization of medication rules, that number has declined steadily, and in 2010 the average horse raced 6.11 times. U.S. horses are less durable and productive than their counterparts in nations with restrictive drug policies. Those nations that ban Lasix have seen no epidemics of bleeding. Hong Kong reports an average of 4.6 bleeding incidents per 1,000 runners.

The rest of the racing world looks on U.S. medication policies with scorn, and this opprobrium partly motivated the Breeders’ Cup’s action. Its president, Craig Fravel, said the phase-out of medications would “ensure that we are competitive with other major international racing events.”

The industry, to its credit, has belatedly gotten serious about the misuse of drugs. It banned steroids and instituted testing to stop illegal “milkshaking,” the practice of administering sodium bicarbonate to reduce horses’ fatigue. But the racing organizations’ efforts to curtail the use of Lasix may prove futile and even counterproductive.

Banning Lasix and other medications in major stakes races is an idea with merit, certainly in the eyes of breeders, because the sport should not be crowning drug-dependent champions who go to stud and beget drug-dependent offspring. But those of us who have lived through the whole Lasix era know the defect of the Breeders’ Cup’s plan.

In the 1970s and ’80s, bettors were obsessed with Lasix because they constantly had to guess what would happen when an underperforming horse got the drug for the first time. They had to guess what would happen when a horse went on or off the medication because he was shipping between jurisdictions with different Lasix rules. After Alysheba won the first two legs of the 1987 Triple Crown while treated with Lasix, he went to New York (where the drug was still banned) and finished a badly beaten fourth in the Belmont Stakes. The main story line of an otherwise compelling Triple Crown series was Alysheba’s drug dependency. It was not a good story for the sport.

The Breeders’ Cup and the American Graded Stakes Committee would create a regular recurrence of Alysheba-in-the-Belmont scenarios by banning Lasix in selected big races. Horses would run on Lasix in ordinary races and then compete without it in the main events — scenarios that would confuse and anger just about everyone who bets on these races. The opinion of the customers ought to count for more than the disapproval of the foreign racing executives that the Breeders’ Cup wants to placate.

The only sensible way to ban Lasix is to prohibit its use in all American races, but that will not happen, because the rules are made on a state-by-state basis, and pro-medication horsemen have more clout on the state level than do the nation’s elite owners and breeders. Industry leaders concerned about medications have plenty of other work to do: The performance of many so-called supertrainers suggests that illegal drug use is rampant, and it continues to corrode public confidence in the game. But the battle over Lasix was decided long ago, and it’s too late to overturn the results.